1. Field of the Invention
The present invention relates to an active energy beam-curable composition which is quickly cured by irradiation with an active energy beam such as ultraviolet radiation and electron beam, which causes neither odor nor cloudiness even when the cured composition is heated, and which has a low viscosity with good operation performance. The present invention also relates to an ink which contains the energy beam-curable composition, and a printer which is accommodates the ink.
2. Description of the Related Art
The active energy beam curing technique is extremely important in a variety of industries including, for example, wood coating, metal painting, and printing, because of various characteristics including, for example, the quick curing speed, the good operation performance generally brought about by the absence of solvent, and the extremely low amount of required energy. Especially, the photo-cationic polymerization is attractive, because of the sufficient possibility to realize a variety of chemical and physical characteristics by means of polymerization of various monomers. In the photo-cationic polymerization, the polymerization is not inhibited by oxygen. Therefore, it is unnecessary to carry out the polymerization in an inert atmosphere. The photo-cationic polymerization is advantageous in that the polymerization can be performed quickly and completely in the air.
However, the conventional active energy beam-curable composition involves the following problem. That is, when the active energy beam-curable composition is further heated after being subjected to coating and curing on a base material such as wood, metal, and paper, any odor is caused by the volatile component thereof, for example, any uncured remaining monomer.
When the active energy beam-curable composition is used at the inside of an instrument or the like, the following problem also arises. That is, when the active energy beam-curable composition itself undergoes a high temperature, any cloudiness appears in the instrument due to the volatile component of the active energy beam-curable composition.
Taking the handling of the active energy beam-curable composition into consideration, it is desirable that the active energy beam-curable composition itself has a low viscosity before being cured. Therefore, when the active energy beam-curable composition contains a photo-cationic polymerizable substance and a polymerization initiator, a low viscosity polymerizable substance such as vinyl ether is used as a diluent in order to lower the viscosity. However, when the low viscosity polymerizable substance such as vinyl ether is used, the following problem arises. That is, when the cured composition is heated as described above, then the volatilization occurs, and the odor and the cloudiness are caused.